Using friction to clamp or climb between two parallel or substantially parallel surfaces is well known in various arts. However, the prior art is devoid of clamping or climbing devices that are capable of clamping or climbing planes that are not parallel or substantially parallel.
Climbing requires two basic capabilities: (1) the ability to achieve (and generally, but not necessarily, release) grip and (2) the ability to move. The latter of these requires the ability to lift and/or lower a person or object so that progress can be made in a desired direction. In addition, extended climbing and/or station-keeping requires some means of maintaining stability so that the person or object can maintain proper contact position and direction for extended climbing distances and periods of time.
Humans have always had the ability to climb certain surfaces without the aid of technology. For example, we can climb trees and cliffs as long as there are surfaces that afford a grip which can be used to support weight.
Technological advances have, however, greatly extended the range of climbable surfaces. For example, rock climbers can scale steep surfaces using high friction shoes while utilizing variations in the surface shape to enhance traction. With devices such as these, even extremely steep or overhanging (or inverted) surfaces can be climbed if there are pits, holes, edges, or cracks that can be gripped for traction. Other technological advances which have increased the types of surfaces we can climb or grip include mechanical jamming devices, pitons, bolts for climbing rock, belts for climbing poles, and the like.
However, these devices all have drawbacks. Mechanical jamming devices require a crack with nearly parallel walls to hold securely. Belts used for climbing poles require a way to reach around the pole, and their use is limited to objects with a relatively small diameter, such as trees or telephone poles. Pitons and bolts damage the surfaces on which they are applied and their use is often accompanied by a time consuming or noisy installation process. The various adhesive systems developed to date leave residue and/or damage the surface.
One of the most significant drawbacks of several of the previously-disclosed systems is that they require two parallel or nearly parallel surfaces. These systems do not achieve high friction coefficients and do not use geometric configurations suited to large-angle gripping. The minimum friction coefficient required to maintain an unloaded grip between walls is defined by the tangent of half of the angle between the walls. This minimum value is not adequate to support an object since it provides no capacity to hold a force other than the clamping force that acts directly between the pads. In practice, a high friction coefficient must be achieved to provide a secure grip capable of supporting objects for gripping and/or climbing purposes. In addition, the geometry of the device must accommodate the non-parallel walls.
Using the tangential relationship for the minimum friction requirement and assuming a reasonably high friction coefficient for metal on rock of 0.3 to 0.5, the maximum angle between walls is about 30 to 55 degrees respectively (not including the reduction in angle required to perform any useful function). These angles, however, are far from the 90-degree angle of typical corners. The designs used in the prior art are not suited to angles of 30 degrees or more between walls. The present invention is.
In practice, the angle required to produce sufficient grip based on the prior art is much less than 30 degrees. Thus, it is generally acknowledged that the walls of a crack must be nearly parallel to provide a secure anchor. The inability of the prior art to accommodate an angle of more than 30 degrees is due to both the choice of materials that do not achieve a high coefficient of friction and designs that cannot accommodate non-parallel geometries well. To achieve a useful grip on surfaces at angles on the order of 90 degrees, a geometry that can accommodate such angles and a friction coefficient that is greater than one (1) are required. The use of high friction materials and the ability to grip surfaces at angles substantially near 90 degrees to each other has not been previously illustrated in the prior art.
Previously-disclosed climbing systems generally fall into two categories: those which can be used to climb natural objects (such as mountains, cliffs, caves and rocks) and those which can be used to climb man-made objects (such as buildings, scaffolding, towers and poles).
Many clamping and climbing devices have been devised for climbing on rock. Many are designed to grip by applying a force between nearly parallel adjacent surfaces (cracks) in rock. Small blocks, wedges, rods, and chocks have been jammed in cracks and used to secure ropes for climbing protection and securing or hauling loads. The rod-jamming system in Bohn, U.S. Pat. No. 5,934,635 (hereinafter “the '635 patent”) and specially-shaped block devices such as Prohaska, Austrian Pat. No. 395945B (hereinafter “the '945B patent”) are examples. However, they are limited in use to jamming in cracks in which the walls of the crack are nearly parallel.
The '635 patent discloses a self-adjusting rock climber anchor device which includes at least one variable length compression arm. The apparatus is formed of two or more arms used to affix the device in a crevice containing parallel or nearly parallel walls. After the device has been affixed in a wedge position in a crevice, a climber may attach a rope to the apparatus for use in ascending and descending the rock face. Such a device is only useful for ascending surfaces containing crevices with nearly parallel walls, such as a mountainside. It is generally not capable of ascending smooth surfaces and/or inside and outside corners where the angle formed by the adjoining walls is approximately ninety degrees.
The '945B patent discloses a climbing wedge capable of insertion into rock cracks. The wedge is formed of convexly formed strips arranged in a direction from its end remote from the load to its end closer to the load. The device is placed into a rock crack by jamming it into the crack until the wedge is firmly secured. Frictional forces hold the apparatus securely in the rock crack. A rope or other such device may then be affixed to the climbing wedge to support an object or enable a climber to ascend and descend the rock face or other such surface. This device is useful for climbing surfaces containing small cracks in which the climbing wedge can be placed. To utilize this device for climbing, the walls of the cracks must also be parallel or substantially parallel, otherwise the device cannot sustain a gripping force capable of supporting heavy objects. The apparatus is not useful for ascending smooth surfaces and/or surfaces containing inside/outside corners angled at approximately ninety degrees.
Lowe U.S. Pat. No. 3,877,679 (hereinafter “the '679 patent”) describes a device based on a cam that is used in similar cracks. Lowe discloses a chock stone device containing a cam used to wedge the main body of the device between opposed pairs of tapered walls (i.e., walls which are parallel or substantially parallel). The device is used by inserting the main body into a crevice and actuating the cam device, thereby causing the upper part of the main body to expand, thereby securing the device between the tapered walls. Objects can then be supported by the device by attaching them to the main body of the apparatus. For example, a climber may attach a rope to the device and use it to ascend a cliff face. This device is only useful for climbing surfaces containing crevices with parallel or nearly parallel surfaces. The apparatus also mars the climbing surface, since the upper portion of the main body contains saw-like teeth used to help secure the device in position. This apparatus is not capable of helping a climber ascend smooth surfaces and/or surfaces in which the tapered walls are not substantially parallel.
There have been many related inventions to the '679 patent, such as: Lowe U.S. Pat. No. 4,645,149 (hereinafter “the '149 patent”), Brodie U.S. Pat. No. 4,712,754 (hereinafter “the '754 patent”), Christianson U.S. Pat. No. 4,643,377 (hereinafter “the '377 patent”) and Taylor U.S. Pat. No. 4,575,032 (hereinafter “the '032 patent”). These cam devices were developed to provide a wider range of crack size accommodation, easier placement and removal, and more security in parallel cracks than previous wedging systems.
The '149 patent describes a camming device that is useful in climbing surfaces containing natural or man-made openings therein and into which a camming device may be inserted to facilitate climbing. The camming device is comprised of cam members containing a serrated arcuate (arm positioned adjacent to a support arm. To utilize the device, the serrated portion is first inserted into the crevice. Next, the support arm is moved to a position perpendicular to the arcuate arm. This causes the serrated portion of the camming device to expand and lock the device into the crevice. The cam device is removed by moving the support arm back to its original position and sliding the device out of the crevice. Since the camming device utilizes a serrated edge, it is only useful in applications in which the surface may be marred. In addition, such a device is not adaptable for climbing smooth surfaces and/or surfaces containing inside and outside corners positioned at approximately ninety degrees.
The '754 patent describes an anchoring device for releasably anchoring within a crack within a rock face, the crack having parallel or substantially parallel walls. The device contains a cam member, a load cable, and an expansion and retraction structure. The cam member has a convexly curved surface. The device is utilized by inserting the cam member into the crack within the rock face and actuating the expansion structure which causes the cam portion of the device to grip the opposing walls of the crack. An object may then be attached to the anchoring device via the load cable. To remove the device from the rock crack, the retraction structure is used to release the cam device so it can be removed from the crack. The geometry of this device allows it to be used to anchor in surfaces containing cracks having parallel or substantially parallel walls. The device is not useful for climbing surfaces having inside/outside corners.
The '377 patent discloses an improved climbing aid formed of one or more pair of opposing cam members, two or more parallel axles on which the cam members may pivot, and a looped cable member connected to the main body of the device to which a load may be attached. To expand and retract the cam members, the device also incorporates spring members which act to simultaneously move the cam members toward an expanded position and an operating member connected to each cam member used to retract the cams. The device is used by inserting the cam member portion of the device into a crack containing parallel or substantially parallel walls and actuating the spring members, thereby causing the opposed cams to expand and affix the device in the crack. A load may then be supported by the device by attaching it to the looped cable member. The device can later be removed from the crack by using the operating member to retract the cams. This device is limited to use on surfaces containing cracks and is not applicable to surfaces containing inside corners and outside corners in which the adjoining walls are not parallel or substantially parallel.
The '032 patent describes an apparatus composed of three (3) opposed cams containing teeth on their outer surface. The cams are attached to a shaft and spring loaded to rotate to their widest point of separation. A pull rod is slideably located within a slot in the handle portion of the device. When the pull rod is manually retracted, it forces the cams to also retract. The device can then be placed inside a crack. When the pull rod is released, the cams return to the open position and grip the internal surface of the crack in a chock-like manner. Similar to the previously described prior art, this device aides in climbing surfaces with natural or man-made cracks, but it cannot be utilized to climb surfaces which are not and must not be marred or surfaces containing inside/outside corners arranged at an angle of approximately ninety degrees.
There are also several systems based on multiple sliding wedges and/or rollers such as Byrne EPO Pat. No. 0323391 (hereinafter “the '391 patent), Frechin French Pat. No. 2553668 (hereinafter “the '668 patent), and Guthrie et al. U.S. Pat. No. 4,643,378 (hereinafter “the '378 patent”).
The '391 patent depicts a self adjusting climbing chock formed of a looped end and first and second cable end sections. A fixed wedge element and a translating wedge element are attached to the cable end sections. The translating wedge element is normally held in a retracted position by a spring. To utilize the apparatus to climb, the chock portion of the device is inserted into a crack and weight is placed on the looped end, causing a spring to expand and the translating wedge element to move away from the fixed wedge element, thereby causing the wedge elements to press against the walls of the crack and support the weight placed on the looped end of the apparatus. The device may be disengaged from the crack by removing the force placed on the looped end of the device. The translating wedge element will then return to its contracted position, allowing the device to be removed from the crack. This device is capable of aiding a climber only on surfaces containing cracks with parallel or substantially parallel walls. This patent does not disclose any method or apparatus of climbing surfaces formed from either inside or outside corners in which the walls meet at approximately a ninety-degree angle.
The '668 patent depicts a nut composed of two adjacent half-wedges. The wedges are joined together by a cable. The wedges can be rotated relative to each other to achieve different wedge geometries. A ring clasp on the rope connecting the two half-wedge can then be used to immobilize the wedges from moving relative to one another. The device can then be inserted into cracks of various sizes by forcing the configured wedge into a crack so that it does not easily slide out. The rope attached to the nut can then be used to aid in climbing a rock wall or other such surface with cracks. However, this device is not capable of aiding a climber in ascending inside or outside corners arranged at an approximate angle of ninety degrees because the wedges, as disclosed, are not designed for use in such a geometry.
The '378 patent discloses a roller-chock climbing aid composed of a wedge shaped chock, a roller, a spring, and a release cable. The wedge shaped chock and roller are arranged next to each other and connected by said spring. When the release cable is pulled downward by a climber's weight, the roller chock moves away from the wedge shaped chock and affixes the apparatus in a crack in a similar manner to the device disclosed by Byrne. To remove the device from a crack, the applied force must be taken off the release cable. The spring connecting the roller to the wedge shaped chock returns the device to its original position, allowing it to easily be removed from the crack. As disclosed, this apparatus is not capable of ascending adjacent corners formed from walls adjoined at approximately a ninety-degree angle.
These multiple wedge devices were developed to achieve the advantages of the cam systems in ease of use and security in application to very small cracks that are too small for a cam design to work. All of these devices have proven useful when properly used in suitable cracks with parallel or nearly parallel faces. They are used to secure safety ropes of people climbing as well as supporting people, temporary shelters, equipment and the like during expeditions. Crack jamming devices have been developed to span a very wide range of crack sizes, yet all of these devices are limited in use to cracks in nearly parallel walls. These devices are useless when the surfaces containing the cracks are not substantially parallel.
In addition to the previously-noted devices for holding in cracks, hooks and other hook-like devices have been used to grip external features projecting from walls. These hooks, however, are severely limited in their application to surfaces that are nearly perpendicular to the direction of the applied force, such as ledges.
Although high friction shoes are commonly used in rock climbing, none of these devices can grip surfaces that are not nearly parallel in nature and none are designed to hold on outside or inside corners that approach right angles.
Drilling and bolting to a rock surface is a means of providing secure attachment to a single surface. Most applications of drilling and bolting are used in rock climbing to leave fixed brackets for mounting protective equipment while climbing. One disadvantage of this approach is that a large supply of components is required since the bolts are left in the wall.
For example, Checkett, PCT App. No. PCT/GB97/00620 (hereinafter the '620 application”) describes a removable and replaceable bolt, which allows the bolt to be removed, but this still requires drilling a hole before placement of the bolt and leaves a hole after removal. Although bolting allows a grip to be achieved on most thick, strong and drillable surfaces, and can thus be used on most rock and many building surfaces, there are many serious drawbacks to the technique. Drilling rock is time consuming, noisy, and requires a lot of power. The hole mars and weakens the rock or building surface. The pressure generated by bolting is also very high, so that the surface must be of a relatively high strength material to hold the bolt when loaded. Thus, drilling and bolting is not a suitable means of clamping when minimizing weight, time, noise, surface damage, and/or power is of value or when speed, stealth, reusability, and/or the ability to leave no trace is required.
Clamping and climbing devices have also been developed for man-made structures. Many skyscrapers and large structures have tracks or other features built into them to aid with building and window washing. Special climbing devices made to fit specific features of specific buildings have also been developed. None of these approaches are suited to general use because they rely on specific features of each building that are not common on most structures or natural surfaces.
Scaffolding is commonly used to overcome the limitations on available building surface climbing and holding technology. Many climbing and clamping systems have been developed for scaffolding, so instead of attempting to climb the building directly, the scaffolding is climbed. Scaffold climbing devices, typified by inventions such as Swager U.S. Pat. No. 3,933,220 (hereinafter “the '220 patent”), Lewis U.S. Pat. No. 4,368,801 (hereinafter “the '801 patent), and Fullam et al. U.S. Pat. No. 5,806,628 (hereinafter “the 628 patent”) are very specific to the features of the scaffolding. All rely on the basic concept of reaching around or inside a consistent feature of the scaffold structure to provide a secure clamp.
The '220 patent discloses a safety clamping device for use by climbers mounted in an elongated slot in a support rail. The clamping device and the support rail contain wedges configured such that the two sets of wedges interlock. The safety clamping device contains a trigger arm which allows the wedges of the clamping device to be disengaged from the wedges of the support rail. The climber can then slide the clamping device to a new position to aid in ascending or descending the structure to which the support rail is attached. This device is only applicable to geometries containing some type of support rail containing wedges and is not useful for ascending or descending natural phenomenon containing an unstructured geometry. This device is additionally not suited for climbing inside or outside corners, even if the adjoining walls are substantially parallel.
The '801 patent depicts a column climbing device for climbing columns such as girders having flanges. The device is designed to be worn on the feet of a climber and is equipped with a gripping member having spaced apart jaws adapted to grip a column flange. The gripping member on each foot is mounted for selective swinging between two positions. In one position, the jaws of the gripping member extend in the direction of the climber's toes. In the retracted position, the jaws extend laterally outwardly and behind the heel of the climber's foot so as to be out of the way when not used in climbing. This apparatus is useful for ascending highly organized, man-made surfaces. It is not designed for use in climbing any other surface geometry.
The '628 patent describes a climbing device for attaching to building frames having a pair of jaw members movable with respect to the other. The spacing between the jaw members may be adjusted using a lever device to permit a user to detachably affix the device to the frame of the building. The climbing device additionally contains a foothold and a harness to support a user. Similar to the apparatus disclosed by Lewis, this apparatus is useful for ascending highly organized, man-made surfaces. It is not useful for climbing surface geometries onto which the jaw members cannot grip.
All of these prior art devices are designed so that a component of the normal force (the force perpendicular to the contacting surfaces) provides a net force that at least partially assists with retaining the device. Although there are some towers with scaffold-like construction, clearly most natural and building structures do not have features that can be grasped in the manner used by scaffold gripping systems; if they were, there would be no need for the scaffold.
There are also many clamping/climbing devices for climbing poles and trees. Johnson U.S. Pat. No. 6,264,000 B1 (hereinafter “the '000 patent”) and Brust WO Pat. No. 59,682 (hereinafter “the '682 patent”) describe clamp systems based on encircling a tree or pole with a belt or rope.
The '000 patent discloses a tree stand and climbing apparatus. The device utilizes a plurality of belts which may be flexible in nature and/or contain teeth. The belts are looped around the tree in a U-shaped manner and attached to a person's body or stand. A person may utilize such a device to climb a tree/pole by alternately moving the belt and the climber's feet up the tree, which results in the overall upward motion of the climber. The climber may also descend the tree/pole in a similar fashion. This invention is useful for attaching a stand to a tree or pole or climbing such an object. However, the object cannot be used to ascend any surface which the belt cannot encompass, such as the corner of a building or a rock face.
The '682 patent discloses a fall prevention device which may also be used for climbing pole shaped objects. The device utilizes a rope or other such object which is wrapped around the pole. On the side of the pole where the ends of the rope meet, the ends are fed through a connecting element. The ends of the rope are then looped back around the post structure along their original path. Each end of the rope is affixed with an attachment structure, such as a loop or clip. A climber utilizes this device for safety by attaching the ends of the rope to some structure located on the climber's body. The force that a climber's weight exerts on the rope during a fall causes the rope to tighten around the pole, thereby preventing the fall. The device may also be used for climbing a pole type structure by relieving the tension from the belt, moving the belt up the pole, and then re-tensioning the belt. In this manner, a climber may either ascend or descend a pole type structure. However, as is the case with other belt devices, this invention is only useful as a fall prevention device on pole type structures and is not readily applicable to other geometries.
Andruchiw U.S. Pat. No. 4,527,660 (hereinafter “the '660 patent”) and Swett U.S. Pat. No. 4,410,066 (hereinafter “the '066 patent”) describe climbing systems based on similar techniques of reaching around a tree or pole combined with a stepwise climbing motion. In addition to reaching around the tree or pole with a belt, it is apparent that a relatively stiff structure such as a hook or closed U reaching part way around a tree or pole can work in a similar manner to a belt or rope.
The '660 patent discloses a pole climbing aid comprising a belt member attached to the waist of the climber as well as a hand grip member which is meant to aid in climbing and serve as an extra precautionary measure. The belt attached to the climber's body is used to climb the pole as is well known in the art. The hand grip member is an additional component of the device which is connected to the belt member via a connection means, such as a rope. The device may include any number of hand grips. As the climber ascends the pole, the hand grip device is disengaged from the pole and repositioned at a higher position on the pole. In this manner, a climber may descend a pole with this apparatus. This device may be used to climb any pole type structure which a belt may encompass and which a hand grip may be attached to. However, such a device may not be useful for ascending large diameter poles because the handgrip could not easily be attached to the pole's surface. The device is not adaptable for climbing most other geometries, such as the corners or surfaces of buildings.
The '066 patent discloses a tree stand apparatus which utilizes a U-shaped frame surrounding the tree to suspend the tree stand at the desired elevation. The device provides a covered frame, with openings in the top and bottom and means to securely close the openings. The tree stand may be fashioned from wood or any other similar lightweight and durable material. The entire frame may be elevated by a single operator. Such a device is only useful in geometries in which a U-shaped frame can encompass the entire object. No other means is disclosed to suspend the tree frame at the desired elevation.
A major disadvantage of such devices is that since they encircle all or most of the tree, they do not easily allow limbs to be passed. Like the scaffold climbing apparatus, none of the tree and pole climbing devices can be utilized for general climbing of common building features.
Ingro U.S. Pat. No. 3,810,515 (hereinafter “the '515 patent”) describes a magnetic crawling device that utilizes magnetic forces to achieve traction to climb and maneuver on walls. Clearly, the requirement of magnetic walls is a severe limitation for many applications, since most walls are not surfaced in and/or made of magnetic material. Such magnetic climbers, in addition to severe limitations on what materials can be climbed, have numerous other problems such as attraction of debris due to the magnetic field and the relatively low forces that can be generated. Although they have application to specific situations, magnetic systems are severely limited and not suited to general use on the majority of surfaces. Ingo also describes use of suction power to achieve attractive force so that a ferrous wall is not required.
You U.S. Pat. No. 4,477,998 (hereinafter “the '998 patent”) describes a system of suction cups on a belt for climbing on walls. The '998 patent describes a wall-climbing toy consisting of a belt drive mechanism with suction cups attached along the surface of the belt. To climb a wall, the toy is first affixed to the wall using the exposed suction cups attached to the belt drive mechanism. As the belt rotates, new suction cups are introduced to the wall surface as old suction cups are forcibly removed from the wall surface. In this manner, the toy may ascend or descend the wall. Such a device will only work on very smooth surfaces to which a suction cup will adhere. Additionally, the device must also be lightweight because the only force affixing the toy to the wall is provided by the suction cups. The device lacks the ability to ascend rough surfaces and the ability to navigate corners.
German Pat. No. 19727421A1 (hereinafter “the '421 patent”) to Schmierer describes a similar tracked suction-cup climbing robot. The '421 patent discloses a wall-climbing apparatus also consisting of a belt drive mechanism with suction cups attached to the surface. The Schmierer device improves on the You device by pairing the suction cups on the belt. By doing so, this device can navigate bumpier surfaces because of the increased number of pads. It also has the capability to carry a larger weight load. However, the device also has the same limitations as other suction cup device. For example, the surface must be relatively smooth or the suction cups will not adhere. This device also cannot navigate corners or other such obstacles.
Winkler WO Pat. No. 37,728 (hereinafter “the '728 patent”) describes a vacuum action climbing system based on suction modules that can be mounted to a user's hands and feet and driven by a vacuum-generating device to allow a person to climb the walls of buildings. The '728 patent discloses a backpack mounted vacuum system and fan shaped suction pads on hands and feet that would allow climbing of relatively smooth and walls and ceilings. All of theses devices require a wall with the proper characteristics for achieving traction. Due to the fact that atmospheric pressure is generally less than 14 psi, there are inherent limitations on the lifting capacity for a given size for any suction based device because adequate area is required to achieve a required force. If a wall is too rough or porous, the suction cups will not work. If the vacuum-generating device disclosed in the '728 patent is capable of achieving adequate suction on a rough surface, then it must continually pump air, requiring an impractical amount of power for climbing many building and natural surfaces. A device capable of producing suction force on rough surfaces efficiently would clearly be useful for clinging to surfaces, but still would not enable extremely long duration gripping, very high forces, or completely silent operation compared with mechanical based gripping systems. Incorporated by reference is co-pending application Ser. No. 09/316,318 which discloses a vortex attractor capable of use in the present invention.
Crabbe British Pat. No. 2,131,475 (hereinafter “the '475 patent”) describes roof top gripping and climbing appliances that utilize high friction material to achieve grip on slanted surfaces such as roofs. The '475 patent describes achieving a coefficient of friction greater than one in experiments. Crabbe achieved an effective coefficient of friction of 1.5 for gritty concrete using high friction surfaces made of foam materials. Required thicknesses suitable for several types of roofing are described. Gripping on roofs of steeper than 45-degree pitch was achieved only for a few specific surfaces and conditions. The invention of the '475 patent, although useful for roofs, has no use in scaling vertical surfaces and thus has no use in most climbing applications.
As stated above, each piece of prior art has its own particular disadvantages, but one of the most basic shortcomings of the prior art as a whole is that nothing disclosed therein is capable of climbing and/or gripping one of the most common surface features—inside and outside corners. Such corners are typically of relatively large opening angle. Often, surfaces meet at approximately 90 degrees in corners. The Applicant is unaware of any prior art which discloses a gripping and/or climbing device that is capable of clinging to and climbing a corner where the walls meet at approximately 90 degrees. The present invention accomplishes this.
Clearly what is needed in the art is a device for gripping and climbing corners utilizing the available adjacent surfaces. An invention that makes use of nearly universally available surface features, requires little power, makes little noise, does not damage the surface, and can be scaled up or down to accommodate a wide range of applications including small robots, humans, or large systems is an advancement of the art and is disclosed herein as the present invention.